1. Field of the Invention
This invention relates to tillage implements, and more particularly to a tillage implement with on-the-go angle adjustable disc blades.
2. Description of the Related Art
Modern tillage implements are generally comprised of a wheeled frame assembly which supports a combination of tillage tools so as to accomplish one or more tillage tasks on each pass of the implement. One of the tillage tools typically found on tillage implements are disc blades. Disc blades are used primarily to cut or chop crop residue on the surface of the soil and mix the residue into the soil as the disc blades pass through the field.
Most conventional implements which utilize disc blades usually have the disc blades arranged in one or more disc gangs. Disc gangs are merely a plurality of spaced apart disc blades attached to a support beam that is in turn connected to the main frame of the implement. The individual disc blades of the disc gang are usually oriented in the same direction and the disc gangs are typically set at an oblique angle to the direction of travel of the implement. This oblique angle of the disc gangs allows the disc blades to better cut and mix the crop residue into the soil. In many conventional tillage implements, the disc gangs are arranged in an "X" configuration with the trailing half of the X configuration having the disc blades oriented in the opposite direction as the leading half of the X configuration. The purpose of the X configuration is to provide for better mixing of the crop residue into the soil and to more evenly level the soil surface.
It should be appreciated that changing the oblique angle of the disc gangs will vary the amount of residue being turned over and worked into the soil. It is often desirable to vary the amount of crop residue left on the surface of the soil in different areas of the field. For example, in areas of a field subject to more severe wind or water erosion, it is desirable, and often required by soil conservation boards, to leave more crop residue on the soil surface to minimize soil erosion. Alternatively, in areas of a field not subject to wind or water erosion, it is desirable to have less crop residue on the soil surface and more of the crop residue turned over into the soil.
Heretofore, few implements allowed the oblique angle of the disc gangs to be varied in order to control the amount of crop residue left on the surface of the soil. One prior art implement which does allow for varying the oblique angle of its disc gangs is disclosed in U.S. Pat. No. 5,462,123 issued to Harlan et al. (Harlan '123). Unfortunately, changing the oblique angle of the Harlan '123 implement, requires the disc blades to be out of the soil. Thus the oblique angle of the disc gangs can not be adjusted while on-the-go. Therefore, there is a need in the industry for a disc implement with discs that can be adjusted while on-the-go to vary the amount of crop residue left on the surface of the soil.
Additionally, in recent years, use of deep tillage implements has become increasingly more popular. Deep tillage implements are used to break up the "hard-pan" or soil compaction layer in the fields. Soil compaction often results in water ponding in the fields and reduces crop yield. Soil compaction is a common problem in many fields and can be caused by repetitive tillage at the same depth by the same implement, working the soil in wet conditions, numerous trips by heavy equipment, heavy rains, and/or lack of crop rotation.
One common problem when using deep tillage tools on fields with a high percentage of crop residue on the surface is plugging of the deep tillage shanks. For example, when using a deep tillage implement on a corn field, the corn stalk residue often gets wrapped around the deep till shanks. As more and more stalks wrap around the shanks as the implement passes over the field, the shanks become so entangled with stalks that the crop residue no longer flows between the spaced apart shanks. Therefore, the implement must be raised out of the soil to remove the entangled stalks from the shanks, resulting in significant down time.
In an attempt to minimize plugging of the shanks, most deep tillage implements now have at least one set of disc gangs preceding the deep till shanks. The discs are intended to cut or chop the crop residue in smaller pieces before the residue encounters the deep till shanks. Many deep tillage implements use two sets of oppositely oriented disc gangs before the deep till shanks, wherein the disc blades of the rearward disc gangs are oriented in the opposite direction as the disc blades of the forward disc gang. One type of such implement is the Ecolo-Tiger implement series sold by DMI. Although orienting the forward and rearward disc gangs in such a manner is an improvement over the single disc gang arrangement in that it minimizes plugging of the deep till shanks, the farmers are still left with the same problems as discussed above, that being, the inability to change the oblique angle of the discs blades while on-the-go to vary the amount of crop residue on the surface or the soil. Thus there is a need in the industry for a deep tillage implement that takes advantage of the oppositely oriented disc blade arrangement discussed immediately above in order to minimize plugging of the deep till shanks, but yet allows the farmer to adjust the oblique angle of the disc blades while on-the-go in order to vary the amount of crop residue left on the surface of the soil.